Microstrip Yagi-Uda antenna

Abstract

A compact microstrip antenna having elements comprising a Yagi-Uda array is provided for use in an apparatus communicating through the antenna. The microstrip Yagi-Uda antenna is adapted for use in an apparatus such as a cellular phone, PDA, laptop computer, or a vehicle having a telematices device.

1. An antenna, comprising:
 a substrate of dielectric material; and 
 a plurality of electrically conductive elements disposed on a surface of the substrate to form a Yagi-Uda dipole array,
 wherein the Yagi-Uda dipole array includes a driven element, a reflector, and at least one parasitic element, the reflector disposed on one side of a dipole, and the at least one parasitic element disposed on the other side of the dipole, and 
 wherein the driven element is separate and distinct from the at least one parasitic element. 
 
 
     
     
       2. The antenna of  claim 1 , wherein electromagnetic energy is coupled from the driven element to one or more of the at least one parasitic element through space and by surface waves in the substrate. 
     
     
       3. The antenna of  claim 2 , wherein the driven element includes a first dipole element and a second dipole element extending colinearly in opposite directions from and perpendicular to a longitudinal axis of the substrate. 
     
     
       4. The antenna of  claim 3 , wherein the first dipole element and the second dipole element have adjacent ends spaced apart at equal distances on either side of the longitudinal axis of the substrate. 
     
     
       5. The antenna of  claim 1 , wherein the at least one parasitic element includes a reflector and at least one director. 
     
     
       6. The antenna of  claim 5 ,
 wherein the reflector is disposed on a first side of the driven element; and 
 wherein each director is disposed on a second side of the driven element. 
 
     
     
       7. The antenna of  claim 5 ,
 wherein the reflector extends linearly across a longitudinal axis of the substrate. 
 
     
     
       8. The antenna of  claim 5 ,
 wherein the reflector is centered upon a longitudinal axis of the substrate. 
 
     
     
       9. The antenna of  claim 5 ,
 wherein the reflector is perpendicular to a longitudinal axis of the substrate. 
 
     
     
       10. The antenna of  claim 5 ,
 wherein a first director of the at least one director extends linearly across a longitudinal axis of the substrate. 
 
     
     
       11. The antenna of  claim 5 ,
 wherein a first director of the at least one director is centered upon a longitudinal axis of the substrate. 
 
     
     
       12. The antenna of  claim 5 ,
 wherein a first director of the at least one director is perpendicular to a longitudinal axis of the substrate. 
 
     
     
       13. The antenna of  claim 1 ,
 wherein the driven element and the at least one parasitic element facilitate a broadcast by the antenna of a signal having a free space wavelength. 
 
     
     
       14. An apparatus, comprising:
 an antenna support; and 
 an antenna mounted on the antenna support, the antenna including
 a substrate of dielectric material, and 
 a plurality of electrically conductive elements disposed on a surface of the substrate to form a Yagi-Uda dipole array,
 wherein the Yagi-Uda dipole array includes a driven element, a reflector, and at least one parasitic element, the reflector disposed on one side of a dipole, and the at least one parasitic element disposed on the other side of the dipole, and 
 wherein the driven element is separate and distinct from the at least one parasitic element. 
 
 
 
     
     
       15. The apparatus of  claim 14 , wherein electromagnetic energy is coupled from the driven element to one or more of the at least one parasitic element through space and by surface waves in the substrate. 
     
     
       16. The apparatus of  claim 14 , wherein the driven element includes a first dipole element and a second dipole element extending colinearly in opposite directions from and perpendicular to a longitudinal axis of the substrate. 
     
     
       17. The apparatus of  claim 16 , wherein the first dipole element and the second dipole element have adjacent ends spaced apart at equal distances on either side of the longitudinal axis of the substrate. 
     
     
       18. The apparatus of  claim 14 , wherein the at least one parasitic element includes a reflector and at least one director. 
     
     
       19. The apparatus of  claim 18 ,
 wherein the reflector is disposed on a first side of the driven element; and 
 wherein each director is disposed on a second side of the driven element. 
 
     
     
       20. The apparatus of  claim 14 ,
 wherein the driven element and the at least one parasitic element facilitate a broadcast by the antenna of a signal having a free space wavelength. 
 
     
     
       21. The antenna of  claim 1  wherein the driven element includes a dipole having a first and a second dipole element extending colinearly in opposite directions from and perpendicular to a substrate axis, the first and second dipole elements having adjacent ends spaced apart at equal distances on either side of the substrate axis. 
     
     
       22. The antenna of  claim 1  wherein the reflector is separate and distinct from the driven element. 
     
     
       23. The apparatus of  claim 14  wherein the driven element includes a dipole having a first and a second dipole element extending colinearly an opposite directions from and perpendicular to a substrate axis, the first and second dipole elements having adjacent ends spaced apart at equal distances on either side of the substrate axis. 
     
     
       24. The apparatus of  claim 14  wherein the reflector is separate and distinct from the driven element.